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1
Rules, Tools and Materials
Objective
Build a model bridge onsite with provided tools and materials within 3 hours with the greatest
structural efficiency.
When
Friday, January 27th
: Check-In/Setup 12:00 pm - 12:30 pm
Bridge Building 12:45 pm - 3:45 pm
Load Testing 3:45 pm - 5:15 pm
Saturday, January 28th
: Check-In/Setup 8:00 am - 8:30 am
Bridge Building 8:45 am - 11:45 am
Load Testing 12:15 pm - 1:45 pm
Awards Ceremony 1:45 pm - 2:15 pm
If School is cancelled on Friday, Jan. 27 or dismissed early, the Battle of the Bridges will
be cancelled and held on the alternate date of Feb.24
If the Putnam is closed on Saturday, Jan. 28 due to inclement weather, the decision to
close will be made by 6:00 am Saturday and a voicemail message will be placed on the
Putnam’s main phone number, (563) 324-1933. The snow date is Saturday, Feb. 25. If
The Putnam is open, the event will be held as scheduled. Contact The Putnam Museum
(563-336-7296) if a team will not be able to compete.
On either date, if the event is cancelled and teams cannot compete on the alternate date, entry
fees will be refunded. If the event is held as scheduled, entry fees will not be refunded;
however pre-paid pizza and pop orders will be refunded.
Saturday teams can pre-order pizza for delivery at 12 pm through the on-line registration
form. Sack-lunches are allowed to be eaten in the Grand Lobby.
Each participant will receive one bottle of water during the bridge build time.
Where
The Putnam Museum
1717 West 12th
Street
Davenport, IA 52804
Financial assistance is available… see Cost
2
Categories
The event is open to any student, grade or age for either Friday or Saturday. The primary reason
for the Friday session is to raise high school team participation as this is the first event of three
for the QC Tech Challenge. A team may consist of two to four people, where all team members
must be signed up on the registration form.
Categories #1-4 are competing for a team trophy and individual medals.
ALL team members must know their team name at registration.
1. Family (Any combination – kids, adults, seniors) – see Rule #10
2. Elementary (Grades 4-6)
3. Middle School (Grades 7-8)
4. High School (Grades 9-12)
5. Professional (Adults only, ≥18 years old – no additional qualifications)
new this year, competing for a Certificate and bragging rights!
Registration limitations:
Friday: 40 teams max (any combination) limited to 8 teams from ANY ONE SCHOOL
Saturday: 40 teams max (any combination), limited to 8 High School teams only
Cost
$25.00 per team
The entry fee includes a bridge material kit and the use of a complete tool set provided at the
event. This does not include entrance to the museum and/or theatre, which is not required to
participate in or watch the event.
Awards
Greatest Efficiency Awards (1
st, 2
nd, and 3
rd) are given to teams in each of the five competitive categories for having
the greatest structural or build efficiencies.
Most Innovative Design An award for the Most Innovative Design will be given to a single team and is judged from all
teams over all categories.
Schedule
Registration Deadline – Thursday, January 26th
, 2017. The registration form and further details
are available at www.qcesc.org by December 16, 2016 (to be announced on QCESC- FB page).
Questions or concerns will be addressed by either the QCESC’s Jeff Melvin
([email protected]) or The Putnam Museum’s Alice Loff ([email protected]).
Financial assistance is available… contact The Putnam Museum @ 563-336-7296
3
Tools and Materials List
Figure 1: The tools and materials supplied in a build kit.
Tools
Provided:
Hack Saw Coping Saw Scissors
Pliers Speed Square 12” Ruler
Yardstick 2 Tubes of Glue
(4g each)
~25 Clothes pins
Utility Knife
Available Upon Request:
Nitrile (Non-Latex)
Gloves
Flat File Square File
Caliper Masking Tape String
Floral Wire 3rd
tube of glue
(you must turn in the 2
empty tubes)
Graph Paper
4
Materials
Bridge Decking (Poster Board)
1 - 21 × 31
4-inches
~ 100 - 41
2× 3
8× 1
12-inches (Craft Sticks)
~ 100 - 6" × 3
4× 1
16-inches (Craft Sticks) ~ 25 - 3
8× 1
16-inches (Stir Sticks)
2 - 36 × 1
4 × 1
4 inches (Bass Wood) 2 - 24 × 3
16× 3
16-inches (Bass Wood)
Rules:
1. Bridges must be designed to accommodate the loading apparatus and be able to support a
weighted toy truck rolled across it. See the testing procedures below for more specifics.
2. The bridge span can be no greater than 24 inches or less than 19 inches, see bridge inspection
checklist diagram below. Teams are provided a wood “fixture” used to model the test rig.
3. The bridge height can be no greater than 9 inches above the deck or 9 inches below the deck. A
combined total height above and below the deck cannot exceed 12 inches. See bridge
inspection checklist diagram below.
4. The bridge width can be no greater than 6 inches or less than 4 inches. See bridge inspection
checklist diagram below.
5. All decisions by the judges are final.
6. Teams will independently build a bridge within 3 hours at the event site using a set of
provided materials. Teams may ask the judges for suggestions. No pre-constructed bridge
components are allowed; however, pre-drawn designs are permitted.
7. Each team will build its bridge with a provided set of standard tools. Only the provided tools
may be used during the build phase and no tool, whole or in part, may be built into the bridge
itself.
8. All bridges will be judged based on the highest structural efficiency rating, as calculated by,
𝐒𝐭𝐫𝐮𝐜𝐭𝐮𝐫𝐚𝐥 𝐄𝐟𝐟𝐢𝐜𝐞𝐧𝐜𝐲 =𝐌𝐚𝐱𝐢𝐦𝐮𝐦 𝐋𝐨𝐚𝐝
𝐁𝐫𝐢𝐝𝐠𝐞 𝐖𝐞𝐢𝐠𝐡𝐭
9. In the event of a structural efficiency tie, the lightest bridge wins. It is up to the team to
decide on the optimum balance between weight and strength.
10. Adults are encouraged to participate in the FAMILY DIVISION only. To ensure fairness
throughout the different age categories, only QCESC volunteers are to work with teams
outside of the FAMILY DIVISION. Violators risk non-refundable team disqualification.
5
Testing Procedure
1. Each team’s bridge is inspected by the judges for compliance with the dimensions specified
in the rules.
2. The bridge weight is recorded.
Figure 3: A bridge spanning the abutments of the test rig.
3. The bridge is placed on the test rig (fig. 3).
Figure 4: The weighted toy truck.
4. To verify the bridge acts as a bridge, a weighted toy truck (fig. 4) with dimensions of ~3x2.5-
inches and a weight of ~5 lb is rolled across the entire length of the bridge.
5. The loading hanger is attached to the bridge and the loading platform is hung from the
hanger.
6. The load weights are placed on the loading platform incrementally until the bridge fails. The
testing judges decide how to load the weight and when to use either the 2 lb or 5 lb weights
while loading.
7. The maximum load that breaks the bridge is recorded.
6
Test Equipment
Test Rig
Figure 5: Different views of the test rig.
The testing rig is a frame made of 1 inch square steel tubing that stands 34 5
8 inches tall. The top
of the frame consists of two arms, each with a 4x8 inch steel top plate and 4x13 inch steel side
plate welded to top outside and bottom inside of the arms, respectively, see fig. 5. The arm and
plate assemblies act as abutments and have adhesive sandpaper attached to them to help keep
bridges from moving while loading. The nominal abutment separation distance with sandpaper is
17 15
16 inches.
Loading Hanger
Figure 6: The steel plate and hanger bolt that make up the loading hanger assembly.
The loading hanger consists of a steel plate with a 3
8 inch hole drilled through its center, see fig.
6. Welded to the top of the plate and in-line with the hole is a washer and nut that a hook bolt is
screwed into.
7
Figure 7: a) A top view of the load hanger attached to a bridge. b) A view down the span of a
bridge with the load hanger attached.
The loading hanger is attached to the bridge by placing the steel plate flat on top of the deck with
the nut facing up. The nut hole is placed in-line with that of the road deck poster board hole, see
fig. 7. The hanger bolt is then fed through the road deck hole from the bottom and screwed into
the nut.
Loading Platform
Figure 8: The loading platform.
The loading platform is used to support the load weight. It consists of two rectangular pieces of 3
4
inch plywood fixed to one another by four eyebolts at the corners, see fig. 8. Each eyebolt has a 1
4
inch braided nylon rope looped through it and fastened together at a steel hoop ring that hangs
from the loading hanger.
Loading Weights
Figure 9: The loading weights.
The loading weights are used to apply a load to a bridge and are placed on the loading platform
when hanging from the loading hanger. Two sized steel weights are used, a gold painted 2 lb
weight and a black painted 5 lb weight, see fig. 9.
8
Figure 10: A bridge spanning the two test rig abutments with the loading equipment attached and
carrying 2 lb and 5 lb weights.
9
Bridge Inspection Checklist
Criteria Acceptable
Bridge Length: 19 − 24 inches
Bridge Height:
≤ 9 inches above deck ≤ 9 inches below deck ≤ 12 inches total
Bridge Width: 4 inches min 6 inches max
Decking across the entire length of the bridge span
Deck capable of supporting weighted truck toy
Assembly area clean/Tools and materials turned in
10
Idea Generating Guidelines
1. Read this document thoroughly and watch the video at the listed link.
(2012) http://www.youtube.com/watch?v=gMgBjHBjcfo&feature=youtu.be
(2013 time lapse) http://www.youtube.com/watch?v=odFWmp6Sio4
2. Explore the internet for bridge building tips and other bridge building competitions.
The Bridge Site - http://www.bridgesite.com/funand.htm
Model Bridge Design - http://www.garrettsbridges.com/category/popsicle-bridges/
Independent Modeling Instructions - http://www.instructables.com/id/Popsicle-Stick-
Bridge/
Independent Modeling Instructions - http://andrew.triumf.ca/andrew/popsicle-bridge/
West Point Bridge Designer 2012 - http://bridgecontest.usma.edu/download.htm
3. See pages 5-6 for bridge building basics provided by the American Society of Civil
Engineers (ASCE).
4. Observe real bridges while traveling.
Modeling Tips
1. Remember, for a real bridge, the important part is the steel and/or concrete structure that
supports the deck the cars drive on not the deck itself.
2. A bridge needs to have a solid, stiff shape along its height, length and width. Meaning the
structure should not bend or twist when weight is place on it. For example, a Popsicle stick is
easier to bend along its flat side than along it edge.
3. A bunch of sticks glued together flat, like a raft, have very little strength and will sag during
testing under very little load (a weight placed on it).
4. String as a structural member should always be in tension, in other words it should always be
stretched.
5. The strongest structural shape is the triangle. A bridge made of a series of triangles will be
very strong, see page 5.
6. A bridge that is symmetrical is less likely to twist when loaded and will probably carry more
weight.
7. A bridge built too tall will have a high moment of inertia, increasing stiffness and strength (a
good thing). However, it may become unstable and topple when under a load (a bad thing).
8. Care should be taken in the deck design to reinforce both the area where the loading plate
rests and the ends where the bridge rests on the test stand with bracing.
11
Bridge Types
Tied Arch Arch Basket Handle Arch
Suspension Truss Cable Stay
Load Path
Compression members shown in green
Tension members shown in purple
Strengthen areas where loads are connected.
Connections
Reinforce joints because bridges are only as strong as their connections.
12
Stability
Use triangular shapes to prevent rectangles from leaning/deforming.
Members in compression such as the Top Chord will tend to buckle sideways during
loading and buckling can be prevented by using Top Lateral Bracing.
Some bridges will twist along their length during loading. Twisting can be prevented by
using a "closed" shape such as a box or triangle as opposed to an "open" U-shape.
Truss Types
Pratt
Warren
Warren with Inverted Pratt
Camelback